Quadrupole order in the frustrated pyrochlore magnet Tb2Ti2O7

TMU International Symposium on "New Quantum Phases Emerging from Novel Crystal Structure"

Takatsu, H.^1,2 ; Taniguchi, T.^1 ; Kittaka, S.^3 ; Sakakibara, T.^3 ; Kadowaki, H.^1

Department of Physics, Tokyo Metropolitan University, Hachioji-shi, Tokyo

192-0397, Japan^1

Department of Energy and Hydrocarbon Chemistry, Graduate School of Engineering, Kyoto University, Kyoto

615-8510, Japan^2

Institute for Solid State Physics, University of Tokyo, Kashiwa

277-8581, Japan^3

关键词: Classical spin;    Long range orders;    Magnetic state;    MC simulation;    Ordered state;    Quadrupole moments;    Quadrupole order;    Tuning parameter;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/683/1/012022/pdf
DOI  :  10.1088/1742-6596/683/1/012022

来源: IOP

【 摘 要 】

We have studied the hidden long-range order (LRO) of the frustrated pyrochlore magnet Tb2Ti2O7by means of specific-heat experiments and Monte-Carlo (MC) simulations, which has been discussed as the LRO of quadrupole moments inherent to the non-Kramers ion of Tb3+. We have found that the sharp specific-heat peak is collapsed into a broad hump by magnetic fields above 0.3 T for H//[001]. This result, qualitatively reproduced by MC simulations, suggests that a field-induced magnetic state overcomes the quadrupolar LRO state, as a similar case of a classical spin ice. The present results support the interpretation that Tb2+xTi2-xO7+yis a unique material in the boundary between the quadrupolar (x xc= - 0.0025) and spin-liquid (x xc) states, where the magnetic field along the [001] axis is a tuning parameter which induces the magnetic ordered state.